<!DOCTYPE html>
<head>
    <meta charset="utf-8">
    <title>三列两行</title>
    <link type="text/css" rel="stylesheet" href="css/public.css" />
    <style type="text/css">
        #S{background-color: yellow;opacity: 0.8;margin: 5px 5px;}
    </style>
</head>
<body>
    <div id="S" style="width: 790px;">这是一行字</div>
<div style="width: 800px;height:400px">
    <div id="S" style="width: 380px;height:370px" class="left">这是左边那个板块</div>
    <div id="S" style="width: 380px;height:370px" class="right">这是右边那个板块</div>
</div>
<div id="S" style="width: 790px;">
    最后一行字
</div>
</body>

</html>